So I was watching the most recent web video of The Woodwright’s Shop, Rachell’s Standing Desk PT. 2 (which can be viewed at: ( http://m.video.pbs.org/video/2365021461/ ), and I don’t understand how Roy’s frame and panel lid allows for any movement of the 10” wide board, with the four part frame neatly mitered at all four corners.

Anyone got any idea how wood expansion doesn’t open one or more corner miters? I’d be most appreciative if someone could explain this one to me.

Thanks in advance for any input you may offer.

-- "I am a firm believer in the people. If given the truth, they can be depended upon to meet any national crisis. The point is to bring them the real facts." - Abraham Lincoln

One makes things as tight as they can during the humid summer seasons, then, during the drier months of winter, the wood will shrink a bit. Whether it is a set of doors, or drawers, or even a lid, that is how is was done back then.

Did the old-timers care IF the board cracked from shrinkage? Not really, because they knew come summertime, that all them cracks would close up again.

bandit571:Sounds good, but then like school teachers, the craftsmen would have to take the summer off each year. LOL.Well, I did look into this somewhat, and according to several sources (web sites) this 10” top could expand and contract as much as 3/16” to 1/4” each year. That seems pretty destructive to the frame, regardless of which way it goes. One would have to find that sweet spot time of year when the board is in the exact middle of maximum & minimum width, to limit movement either way to about 1/16” or so.This one has me stumped.

-- "I am a firm believer in the people. If given the truth, they can be depended upon to meet any national crisis. The point is to bring them the real facts." - Abraham Lincoln

Oldtool I would not use that construction where I live. I almost used the same joinery on a coffee table. I used tongue and groove with butt joints not miters. I also pinned the ends. It is still together with no movement.I also hate miters. There the weakest joint out there. IMHO

I’ve seen lots of cabinet doors where the center panels are “floating” in the styles/rails. I always thought they were built this way to acommodate expansion & contraction. That mentioned, I built a cherry table for the kitchen about 20 years ago, all loose tennon – no nails or screws, with the exception of 6 screws used to keep the top on. I made elongated holes in the frame for the screws, and very lightly tightened, to hold the top in place. I originally made the top 40 inches wide. Depending on the season/humidity, it is generally 1/8th + or – the original 40 inches.

I think Roy spent most the time showing how to make the top, not explaining how it was glued together. As Roy says on many of his shows”well you get the Idea” leaving the glue up to your imagination. If he made elongated holes in the 3 tenons and used pegs to hold the bread board ends on just gluing the center tenon plus making the panel short enough in the sides to allow moment,then all is good re wood moment. If I remember right Roy’s show is shot in one take so he’s lucky to get the idea of what he’s trying to make across at all. I always enjoy his show.

Topo,in the panel above there is no shoulder to butt up against. The grooves are interlocking so when the panel expands, as it inevitably will, there is a gap for it. Think of the grooves as a a labyrinth joint. If I made a cutaway view you would see that there is a gap hidden inside to take up the expansion. I’ll see if I can find an illustration and post it since I’m not very clear in my explanations. You should have seen me trying to figure the damn thing out ;{

-- "Aged flatus, I heard that some one has already blown out your mortise." THE Surgeon ……………………………………. Kevin

I did watch the video and it seems to me that there is no accommodation for expansion that I can see. His breadboard ends are made to not inhibit expansion but I do not see how he allows for movement at the miters.

The chest I posted above has been in use by my grandson for two years now and the mitres are as tight as when I built it. The joints on the top are mitered mortis and tenon. The sides are normal mortis and tenon . You can see the panels movement as the seasons change but the joints are tight and no gaps.

-- "Aged flatus, I heard that some one has already blown out your mortise." THE Surgeon ……………………………………. Kevin